161211157 has 2 divisors, whose sum is σ = 161211158. Its totient is φ = 161211156.

The previous prime is 161211151. The next prime is 161211199. The reversal of 161211157 is 751112161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 127035441 + 34175716 = 11271^2 + 5846^2 .

It is a cyclic number.

It is not a de Polignac number, because 161211157 - 2¹⁵ = 161178389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161211151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80605578 + 80605579.

It is an arithmetic number, because the mean of its divisors is an integer number (80605579).

Almost surely, 2^161211157 is an apocalyptic number.

It is an amenable number.

161211157 is a deficient number, since it is larger than the sum of its proper divisors (1).

161211157 is an equidigital number, since it uses as much as digits as its factorization.

161211157 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 420, while the sum is 25.

The square root of 161211157 is about 12696.8955654522. The cubic root of 161211157 is about 544.2499088303.

It can be divided in two parts, 1612 and 11157, that added together give a square (12769 = 113²).

The spelling of 161211157 in words is "one hundred sixty-one million, two hundred eleven thousand, one hundred fifty-seven".